Field of the Invention
The invention relates to a compressor blade or vane and a compressor using such a blade or vane.
German Patent DE 31 41 948 C2, corresponding to U.S. Pat. No. 4,431,376, describes a blade or vane with a conical blade or vane section for the compressor of a gas turbine. It is stated that when gas flows at high velocity through blades or vanes of a compressor disposed in rows, shock waves can be experienced. The gas flows in a boundary layer along the surface of the blades or vanes that are affected. Separation of that boundary layer from the blade or vane surface can occur because of a shock wave. That causes aerodynamic losses. Those losses limit the efficiency of the blades or vanes. Such losses are of particular importance in a transonic flow field, i.e. in a flow field which contains adjacent regions of local subsonic velocity and local supersonic velocity. It is possible to optimize the section of the blade or vane in order to reduce those losses. That patent specifies a blade or vane with a conical blade or vane section, a profiled suction surface and a profiled pressure surface. The blade or vane has good aerodynamic performance capability and can also be manufactured in a simple manner. The objective of that device is further optimization of the efficiency of a compressor blade or vane.
An aircraft propeller with specially configured propeller blade sections is described in U.S. Pat. No. 4,773,825. The propeller blade sections are constructed in such a way that different loading conditions can be dealt with during a flight operation, for example in a climb or cruise phase.